Milk, Does It Do A Body Good? Part 3: The Raw Debate - A Tale of Two Milks
Posted May 27 2008 6:13am
Today is the part of the dairy issue that is probably most important to most of us here and is also the piece of the puzzle that throws most of what was put together for the last post into question. We're going to look at some of the differences between real, fresh, raw, unpasteurized, unhomogenized milk and the conventional pasteurized, homogenized stuff.
Raw vs. Pasteurized/Homogenized
Conventional wisdom holds that milk is an inherently dangerous breeding ground for bacteria which must be rendered sterile before touching the lips of a human. We need look no further than MSNBC for a prime example of this thinking:
Despite potentially serious health risks, demand for unpasteurized, or raw, milk is growing among consumers concerned about chemicals, hormones and drugs.
So what's the real deal? Is raw milk the best thing since beer was paired with pizza or is it a ticking time-bomb waiting for the inevitable day when you will be hit with Listeria, Campylobacter, or some other nasty microscopic creature? Let's jump in.
First, what exactly is that white stuff that comes in those plastic jugs at Kroger, Albertson's, etc? I hear you saying, "Uhh...Scott, it's milk." Sure, but let's dig a little deeper. What about all of those various jugs with different labels? Skim, 1%, 2%, whole, organic, and even milk for people that are lactose-intolerant. Yes, that's right; some manufacturer actually developed a market for "milk for people that can't drink milk". Genius!
Quickly, skim milk is less than 0.5% milk fat by weight (5% of calories) and 1% milk is 1% milk fat by weight (23% of calories), while 2% is 35% of calories from fat. Whole milk is 3.5%+ milk fat, with about 50% of calories from fat.(1) Then there's the organic milk, which means the cows were fed organic feed, typically grains, and also were administered no antibiotics or hormones. Your guess is as good as mine on what "Lactose Intolerant Milk" is. I assume either the lactose is removed or the lactase enzyme is added. Something else that's in your 1% and 2% milk is powdered skim milk. Doesn't sound like pure milk to me.
All of these various milks have gone through two methods of processing: pasteurization and homogenization. Pasteurization is a process of heating the milk to kill off bacteria - all bacteria. Homogenization breaks down the fats by forcing the milk through small orifices, which changes the size of the fat globules and keeps the fat in suspension rather than allowing it to separate as a cream layer.
And then there's this fancy new milk that seems to be all the rage, "raw milk". What exactly is that? It's milk. Fresh from the cow. No pasteurization. No homogenization. Just milk, straight up, on the rocks, neat, however you want it, but it's as Mother Nature intended. It's a product of evolution, not a product of industrialization. As Mark McAfee of Organic Pastures Dairy says:(2)
"When mothers nurse their babies, do we make a point of saying that the babies are drinking 'raw' milk,"
The point is that "raw milk" is real milk and the stuff in the grocery case is something other than milk. Let's contrast the two.
A Tale of Two Milks
When milk makes its entry into the world, it is a combination of water, fat, protein, carbohydrates, bacteria, vitamins, minerals, and immunoglobulins. There are probably a few other things in there too, but that's the important stuff. All of these are present in raw milk. All of these are not present in pasteurized/homogenized milk.
As mentioned above, pasteurization kills off all bacteria, even the beneficial ones. You know that smell and taste that you get when you leave pasteurized milk in the fridge for a week too long that we call "sour milk"? That's not really sour milk. That's rancid milk. Raw milk, due to the good bacteria, actually sours properly and is a usable product. The good bacteria that remain in the milk are able to contain the bad bacteria that proliferate in pasteurized milk, producing a soured milk that is more easily digestible (and is used for nourishment of invalids). Eventually, you'll get sour cream. You can actually leave raw milk on your counter and the worst that happens is it sours. Don't try this with pasteurized milk unless you want the neighbors calling the cops due to the smell of a dead body emanating from your house.
What about other changes in the milk from heating it? Vitamin C content is reduced. Vitamins A, D, and E are reduced, though that's irrelevant if you're drinking fat-free milk as these fat-soluble vitamins won't be assimilated anyway. The heat also reduces the effectiveness of the water soluble vitamins. B6 and B12 are destroyed. Lipase, an enzyme that helps break down fat, is gone as well.(3) Iodine is reduced by 20%.(4) And if we return to those bacteria that were killed off above, we see that some of them produce the lactase necessary to process the lactose in milk. That's why many lactose-intolerant people can drink raw milk.
Another aspect of the debate is the use of rBGH, or recombinant bovine growth hormone, to increase milk production. This hormone, also known as rBST, or recombinant bovine somatotropin, was approved for use by the FDA in 1994. From an animal welfare standpoint, studies have shown that administration of rBGH has detrimental effects.(5) An 11% increase in milk production comes at the cost of "a nearly 25% increase in the risk of clinical mastitis, a 40% reduction in fertility and 55% increased risk of developing clinical signs of lameness."(6) If you buy into the argument (and how can you not?) that the food product, be it meat, milk, or eggs, is only as good as the source, this is disturbing news.
But rBGH administration also increases the levels of insulin-like growth factor 1, or IGF-1, in the milk. This is a hormone that is identical in both the human and bovine species. So what does it do? IGF-1 is responsible for cell growth. And since studies have shown that increased signaling through the IGF-1 pathway increases the risk of certain cancers (cancers are just rogue cells of you, after all), this doesn't look good for increasing IGF-1 levels in milk.(7)
Then there's the simple fact that Monsanto, the only producer of rBGH, doesn't want consumers to know what's in the products they're consuming, nor how the source of their food was treated. Monsanto has sued companies that declare that their cows are raised without artificial growth hormones on their milk labels, though the FDA allows such a claim with the caveat that "No significant difference has been shown between milk derived from rbST-treated and non-rbST-treated cows," a caveat which is not required for labels like "No MSG" or "no preservatives".(8) Recognize that this company is determined to keep you from knowing anything about your food. They also work hard to make sure there is never a mention of genetically modified anything on any food labels, but that's a story for another time. Monsanto pressured Fox to not run a story that was less than glowing regarding this hormone.
Some countries have banned the use of rBGH outright: Canada, parts of the European Union, Australia, and New Zealand. And consumer pressures are forcing many companies to adopt rBGH-free milk as their standard. Kroger, Safeway, Chipotle, Publix, Starbucks, and others have all began selling rBGH-free milk, many pledging to get rid of milk from cows treated with synthetic hormones.
Here's an amusing point: any nutritionist worth his or her salt knows that low-fat dairy is an essential food group. They typically prescribe lots of unprocessed foods like whole grains, lean meats, vegetables, fruits, and low-fat dairy. But let's back the train up for a second...dairy isn't naturally a low-fat substance, which makes "low-fat dairy" a processed product by default. Add in pasteurization and homogenization and you're dealing with a super-processed product. And let's not forget that there is a dried skim milk powder added to 1% and 2% milk, another obviously processed component. So why would someone that is touting unprocessed products also propose low-fat dairy? I think we all know the answer.
So why do I say that this discussion throws the data in my last milk post into question? Because you won't find any studies conducted with raw milk. I searched PubMed and found none, but if you come across one, feel free to share it in the comments. Considering that raw milk and the stuff in most stores are two very different products, it is virtually impossible to extrapolate from studies on the "cooked and crushed" stuff to fresh, unmolested milk.
That wraps up the discussion of raw dairy vs. pasteurized dairy. One more installment to go in which I'm going to drop my thoughts on the proper role of dairy in the diet.